Damper-regulating means for furnaces



W. H HOLT. DAMPER REGULATING MEANS 'FOR FURNACES.

APPLIfiATION FILED F EB- 24, 1920- Patented J qne 27, 1922." v

llllll WILLIAM H. HOLT, onsoivran'a, NEBRASKA? s I i 3 DAMPER REGULATING MEANS FOR Flfl'RlYl'l-HZIEIS.-

To all whom it may coacern."

Be it known that 1, WILLIAM H. How, a citizen of the United States, residin at Omaha, in the county of Douglas and tate of Nebraska, have invented certain new and useful Improvements in Damper-Regulating Means for Furnaces, of which the fol lowing is a specification, reference being had to the accompanyingdrawings. 7

This invention relatesto means for regulating the dampers on all makes ofhot air furnaces, and particularly to devices de signed to operate automatically upon a rise in temperature beyond a predetermined point to close the damper and openthe check draft of the furnace, and, designed upon a fall in temperature beyond a predetermined degree to open thedraft damper and close the check draft. a

The general object of my invention isto provide a very simple means to this end which is controlled entirely by a diaphragm disposed within an expansion chamber connected to the furnace so that when the heat rises beyond a predetermined degree, the diaphragm will be forced outward, this diaphragm being operatively connected to the check draft and the damper respectively so as to close the damper and open the check draft, or vice versa, when the heat falls below a predeterminedpoint.

A further and important object is to provide means whereby-,the time of operating the damper and the check draft and the ex tent to which the damper will be opened may be regulated, and particularly 130jp1'0V1d6 a diaphragm operated arm, a flexible connection between the arm and the damper, and provide means whereby the flexible connection maybe tightened or slackened to thus control the time and degree of opening of the damper.

Other objects will appear the course of the following description.

My invention is illustrated in the accompanying drawings, wherein I V Figure lis a side elevation of ahot air furnace with my attachment; applied thereto, the top of thefurnace beingpartly in section; p V I Figure 2 .is a sectional viewthrough the top of the expansion chamber;

Figure 3 is a transverse section through the take -up device for thechainQOo;

' Specification of Letters Patent; June 27 7 Application filed February 24, 192 0; Serial No. 36 0,'1 l0. I I i I Figure 4t a front elevation of the part shown 1n'F1gure3;

Figure: 5 is a section on the l ine 5. 5 of Figure 3.-

suitable construction, but 'which is illus- .tratedasa hot air furnace. Disposed above the top of the furnace and resting on the furnace casing isan expansion chamber 11 of sheet metal or other suitable material,

.closed at its upper end vby means of aYdiaphragm 12. .Thisdiaphragm is bolted, rivthe flange 13 of the expansion chamber. Mounted upon the expansionchamber, as by is, a lever 15.

hub 16, and attached to thexupper face of the diaphragm and extending? upward therefrom is a Referring to these/drawings, lOsdesig- I nates the furnace, which may be of any Veted or otherwise attached at its margins to a 7 pin or stud '17 which extends through thls central boss 16 and is pivotally vconnected or rockingly connected ,to the lever 15, which in turn isopivoted, as at 18, I

upon the upper end of the arm '19 .of'the bracket. engages the longyarm of the lever 15, and the extremityof the shortiarm of the lever is operatively,connectedgbyia chain 20,'in

a manner which will belater stated, to the draft damper 21. The opposite end of the arm 15, that is the extremity of the long' arm of the lever 15, is connected by means of aflexible connection 22 to a check draft 23. j Y

It will beobvious now sionthediaphragm will rise orbe forced upwardand this will force upward on the long arm of the lever 15, thus depressing the short arm ofthe lever, relaxing the strain on the flexible connection 20, and permitting vor causing the damperQl to close and at the same. time openingthe check draft, thus dampening the fire and thereby reducing the heat. If, onthe otherrhand, the heat jfalls below a predetermined point, the dia- .phragm 12 will move downward, thus lower- .ing thelong end of the lever 15 and raising the short end thereof, and lifting the damper 21 and at the, same time perupon It will be seen that the pin 17 that under, exp anm i s h ncheok, dra t to se, thus :adi I i mitting more draft to the fire and causing it to burn more briskly.

One of the important features of my invention is the provision of means whereby the degree of slackness in the chain 20 may be controlled to thus control the degree of opening of the damper and the period at which this damper will open. To this end I pivot in any desired manner upon the short arm of the lever 15 a casing 24 within which is disposed a reel 25 mounted upon a shaft 26 which extends out through the front of the reel casing and is provided with a pointer 27. This pointer 27 moves over graduations 28 on the front of the reel casing, and the pointerconstitutes means whereby the shaft 26 may be rotated to rotate the reel to thus wind up or unwind the flexible connection 20. The graduations may be in the form of degrees, as for instance, 50, 60, and 80, corresponding to temperatures of 50, 60, 70 or 80.

It will be obvious that if the chain 20 is slack, the lever 15 may move through a relatively considerable distance without tightening the chain 20 so as to cause the opening of the damper, and that the degree of opening of the damper may be controlled in the same manner, as, if the chaln is slack, it will not begin to open until after the lever 15 has moved some little distance, and it will be only partially open when the lever 15 is fully opened, and on the other hand if the chain 20 be taut,-it is obvious that the least movement of the lever 15 will cause a corresponding movement of the damper, and a full movement of the lever will cause a full move ment of the damper.

The expansion chamber 11 communicates with the upper portion or hot air drum of the heater body 10 by means of a very small opening 29. In ordinary practice this opening'will only be about 3; in diameter, and while the expansion chamber 11 may be formed integral with the top of the furnace body or casing, yet it might be made separate therefrom and held in position thereon by means of a plurality of guy wires or like members 30 having hooks at their lower ends to engage beneath the flange at the top of the stove, and with turn buckles 31 whereby the tensionof these guy wires may be descreased or increased so as to hold the expansion chamber-firmly down in place and in close engagement with the furnace top. The bottom 32 of the expansion chamber is preferably concave, and preferably the lever arm is provided with abalance weight 33. The expansion chamber may be made of copper of about 26' gauge, and in practical use I find it advisable to make it about 7" in diameter and 10 high. The perforation 29 in 4 the top of the furnace permits the heat in the 'dome of the furnace to come in direct contact with the bottom of the expansion c'ahmber,

thus heating the air in the expansion chamber and making it extremely sensitive to the different temperatures inside the hot air dome of the furnace. The top of the furnace outwardly of the expansion chamber may be insulated by a covering 34 of dry sand or by suitable insulatingmaterial of any character. This confines the heat to the bottom of the expansion chamber.

In the operation of'this device, the balance of the lever 15 is so adjusted by means of the counterweight 33, if the air in the expansion chamber contracts, the diaphragm 12 will sink and the piston or pin 17 lowers by gravity, thus lowering the long arm of the lever, and when, on the other hand, the air in the expansion chamber expands, the diaphragm will rise, lifting the pin and the long arm of the lever 15.

In the use of this construction, when sufficient heat is delivered to warm the. room to the desired temperature, the air within the expansion chamber expands and lifts the diaphragm, thus I gradually closing the damper 21, which has been heretofore open, and at the same time opens the check draft 52in the stack. The point of adjustment for a given temperature is controlled by shortening or lengthening the chain 20 on the damper, and this is done, as heretofore described, by adjusting the reel to take up the slack, the reel being adjusted in connection with the dial of graduations on the face of the reel which show where to set the damper to give the temperature desired. Af-

ter once being set, there is no necessity for further adjustment unless the operator wishes to lower the temperature of the rooms 8 during the night, for instance, or wishes to raise the temperature of the rooms during the day.

Assuming that the damper controlling reel has been set at the desired temperature, if then there is the slightest drop in temperature, the cold air returning to the furnace dome be reheated and there is not sufficient heat for it, this cool air or the reduction of temperature within the furnace causes the air in the expansion chamber to contract and open the damper so as to feed more air to the fire. If the register of a cold room is open, the damper instantly takes care of the extra amount of hot air needed. Should the operator desire the rooms to be warmer, he then moves the indicator hand to 60, 7 0 or 80, as the case may be, which opens the damper a little wider, which takes more expansion to close the damper. Of course the check draft in the stack will open according to the above mentioned temperature, thus absolutely stopping the fire and preventing same from wasting away up the smoke stack. 7

When this device is placed on the furnace, the chamber 11 contains only air at atmospheric pressure, and at no time is there more than ten ounces of pressure while in operation. I am aware that other regulators have been proposed for controlling the draft damper and the check, draft damper, but these regulators control the dampers by the heat at the furnace and not from the heat in the room. In my construction, the movement of the damper and of the check draft takes place in accordance with the cold or hot air in the heating dome or air drum of the furnace and does not depend upon the overheating of the rooms and the consequent wasting of the fuel before closing the clampers. With my construction, you may fully charge the furnace with coal regardless of the outside weather and yet keep the rooms at the same temperature without changing the setting of the dampers, it being only necessary to change the damper position when the operator desires to have a different degree of heat in the rooms. This device holds this heat until the heat has been utilized by the circulation of air in the rooms. Therefore, this device does not send a great portion of the heat up the chimney, nor does it overheat the furnace. It will be seen that this device is very simple, that it is easily made in the form of an attachment to hot air furnaces, and that it is very quickly installed.

While I have illustrated a preferred form of my invention which I have found to be thoroughly effective in actual practice, yet I do not wish to be limited thereto, as it is obvious that many changes might be made in the details of construction and arrangement of parts without departing from the spirit of the invention.

. I claim 1. The combination with a furnace having a top and having a damper and a check draft, of an expansion chamber mounted upon the top of the furnace, there being a perforationwhereby hot air may pass from the furnace into contact with the expansion chamber, a diaphragm forming the upper end of the expansion chamber and flexed by the expansion or contraction of the air within the expansion chamber, a lever associated with the expansion chamber and carrying a counterweight, an operative connection between said lever and the dia phragm whereby the lever will be shifted by the flexing of the diaphragm, flexible connections between the opposite ends of the lever and the check draft and damper respectively, and means whereby one of said flexible connections may. be adjusted as to length whereby to secure a variable opening of the element to which it is connected.

2. The combination with a furnace having a top and having a damper, and a check draft, of an expansion chamber mounted upon the top of the furnace, there being a perforation whereby hot air may'pas s from the furnace into contact with the expansion chamber, a diaphragm forming one end of the expansion chamber and flexed by the ex-.

pansion or contraction'of the air within the expansion chamber, va' lever pivotally mounted in connection with the expansion chamber and carrying a'counterweight, an operative connection between said lever and the diaphragm whereby the lever will be shifted. by the flexing of the diaphragm, flexible connections between the op osite ends of the, lever-and the check dra t and damper respectively, and means whereby one of said flexible connections may be adjusted as to length whereby to secure a variable opening of the element to which it is connected, said means comprising an adjustable take-up for the slack in the connection.

3. The combination with a furnace having a top and having a damper and a check draft, of an expansion. chamber mounted upon the top of the furnace, there being a perforation whereby hot air may pass from the furnace into contact with the expansion chamber, a diaphragm forming the upper end of the expansion chamber and flexed by the expansion or contraction of the air within the expansion chamber, a lever pivotally mounted in connection with the expansion chamber and carrying a counterweight, an operative connection between said lever and the diaphragm whereby the lever will be shifted by the flexing of the diaphragm, and flexible connections between the opposite ends of the lever and the check draft and damper respectively, and means whereby one of said flexible connections may be adjusted as to length whereby to secure a variable opening of the element to which it is connected, said means comprising a winding device upon which the flexible connection is adapted to be wound, and means for shifting the winding device any desired predetermined amount and holding it in shifted position.

In testimony whereof I hereunto afiix my signature.

WILLIAM HQHOLT. 

